import java.util.Random;

import lab.Color;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;

/**
 * Test case for the lab.Color class.
 *
 * @author Franck van Breugel
 */
public class ColorTest {
	/**
	 * Tests the constructor and accessors for each RGB combination.
	 */
	@Test
	public void testConstructorAndAccessors() {
		for (int r = Byte.MIN_VALUE; r <= Byte.MAX_VALUE; r++) {
			for (int g = Byte.MIN_VALUE; g <= Byte.MAX_VALUE; g++) {
				for (int b = Byte.MIN_VALUE; b <= Byte.MAX_VALUE; b++) {
					Color color = new Color((byte) r, (byte) g, (byte) b);
					Assertions.assertNotNull(color, "Constructed object is null");
					Assertions.assertEquals(r, color.getRed(), "Accessor of red returns the incorrect value");
					Assertions.assertEquals(g, color.getGreen(), "Accessor of green returns the incorrect value");
					Assertions.assertEquals(b, color.getBlue(), "Accessor of blue returns the incorrect value");
				}
			}
		}
	}

	/**
	 * Tests that the constant BLACK is not null.
	 */
	@Test
	public void testBLACK() {
		Assertions.assertNotNull(Color.BLACK, "The constant BLACK is null");
	}

	/**
	 * Tests the equals method.
	 */
	@Test
	public void testEquals() {
		for (int r = Byte.MIN_VALUE; r <= Byte.MAX_VALUE; r++) {
			for (int g = Byte.MIN_VALUE; g <= Byte.MAX_VALUE; g++) {
				for (int b = Byte.MIN_VALUE; b <= Byte.MAX_VALUE; b++) {
					Color color = new Color((byte) r, (byte) g, (byte) b);
					Object object = new Object();
					Color copy = new Color((byte) r, (byte) g, (byte) b);
					Assertions.assertFalse(color.equals(null), "null is equal to a Color");
					Assertions.assertFalse(color.equals(object), "An Object is equal to a Color");
					Assertions.assertTrue(color.equals(color), "A Color is not equal to itself");
					Assertions.assertTrue(color.equals(copy), "A Color is not equal to another color with the same RGB values");
				}
			}
		}
	}

	/**
	 * Tests the equals method for different Color objects.
	 */
	@Test
	public void testEqualsRandomly() {
		final int CASES = 100000000;
		Random random = new Random();
		for (int c = 0; c < CASES; c++) {
			byte b = (byte) (Byte.MIN_VALUE + random.nextInt(Byte.MAX_VALUE - Byte.MIN_VALUE));
			byte r = (byte) (Byte.MIN_VALUE + random.nextInt(Byte.MAX_VALUE - Byte.MIN_VALUE));
			byte g = (byte) (Byte.MIN_VALUE + random.nextInt(Byte.MAX_VALUE - Byte.MIN_VALUE));
			Color one = new Color(r, g, b);
			b = (byte) (Byte.MIN_VALUE + random.nextInt(Byte.MAX_VALUE - Byte.MIN_VALUE));
			r = (byte) (Byte.MIN_VALUE + random.nextInt(Byte.MAX_VALUE - Byte.MIN_VALUE));
			g = (byte) (Byte.MIN_VALUE + random.nextInt(Byte.MAX_VALUE - Byte.MIN_VALUE));
			Color other = new Color(r, g, b);
			Assertions.assertEquals(one.equals(other), 
					one.getRed() == other.getRed() && one.getGreen() == other.getGreen() && one.getBlue() == other.getBlue(),
					"Comparison of two Colors failed");
		}
	}
}